Little helper used to parse a natural time string such as "7 seconds" and convert the textual representation into seconds. This could be reduced into a single function, but this is how it was originally used.

NaturalTimeSpan.py

import re

class NaturalTimeSpan:
    time = 0
    
    def __init__(self, time_string):
        BAD_STRING = 'Unsupported format string provided: %s'
        matches = re.search('^(?P<quantity>\d+)\s+(?P<format>second|minute|hour|day|week|year)s?$', time_string)
        
        if not matches:
            raise Exception(BAD_STRING, time_string)
        
        multiplier = {
            'second': 1,
            'minute': 60,
            'hour'  : 60 * 60,
            'day'   : 60 * 60 * 24,
            'week'  : 60 * 60 * 24 * 7,
            'year'  : 60 * 60 * 24 * 7 * 365
        }.get( matches.group('format'), None )
        
        if not multiplier:
            raise Exception(BAD_STRING, time_string)
        
        self.time = multiplier * int( matches.group('quantity') )
    
    def get_time(self):
        """ Returns the time span in seconds """
        return self.time